1. Field of the Invention
The present invention relates to battery packs and, more particularly, is directed to a rechargeable type battery pack for use in a power supply of a video tape recorder having a built-in camera, for example.
2. Description of the Relevant Art
Conventional battery packs that are utilized as a power supply of electrical machinery and apparatus such as a video tape recorder having a built-in camera, a portable video tape recorder or the like include, fundamentally, plus and minus terminals used to charge and discharge a battery and a so-called T terminal used to output the temperature detected in the inside of the battery pack.
Generally, battery packs made by different makers are different in specification, shape, terminal structure, detection hole or the like. Therefore, battery packs made by different makers are not compatible with each other and a battery pack made by a certain maker cannot be attached to the apparatus made by different makers.
According to the conventional battery packs, an information signal such as data representative of capacity displayed on a battery charger when a battery is charged, capacity displayed on the electrical machinery and apparatus when the battery is discharged, type of battery cells used when the battery charger is switched, the number of battery cells used when the charge and discharge capacity is switched and when intensity of video light is switched or the like cannot be output. Hence, the conventional battery pack is requested to have an output terminal to output such information signal.
As a so-called 8-mm video tape recorder that is one of video tape recorders having a built-in camera becomes more popular on the recent market, it becomes clear that fraudulent battery packs having a compatibility with battery packs that are manufactured by a particular maker are manufactured and become commercially available on the market of the whole world. Such fraudulent battery packs spoil the legitimate market.
A conventional battery pack has no output terminal to output an electrical signal that can identify a battery pack manufacturer. Therefore, in order to discriminate fraudulent battery packs from battery packs of entirely real-manufacturer maker and to remove the same from the market, makers have no choice but to print logotypes of company names, marks that indicate battery packs of entirely real-manufacturer make or the like on the surfaces of the battery packs.
Insofar as battery packs are manufactured in the same size and shape, it is unavoidable that battery packs are made compatible. For this reason, it has been requested that fraudulent battery packs are discriminated from battery packs made by a certain maker and removed from the market by some mechanical arrangements.